Clouds of smog have settled on Delhi after Diwali. PM 10 and 2.5 levels have breached hazardous levels. Is this a possible tipping point?

Yes, it is definitely a possible turning point. Delhi is not the first city, nor will it be the last, to struggle with extreme pollution. Toxic air is a side effect of industrialisation; the collateral damage of “development”. Take the great London smog of December 1952 as an example, thought to have killed 4,000 people prematurely. This incident helped pave the way for England’s Clean Air Act in 1956, which established “smoke control areas” in several cities, led to power stations being relocated away from urban centres etc. So, current conditions in Delhi can galvanise society and politicians into finally taking serious action to clean up the air too.

You lived and reported in China in the run-up to the Beijing Olympics. What lessons can India learn from China?

My book argues that although Beijing may still be a poster child for what not to do on the issue of pollution in the international imagination, China has actually undertaken far-reaching and difficult measures to ensure that the worst is over. According to NASA satellite data, the PM 2.5 levels across India got worse by 13 per cent between 2010 and 2015, while China’s steadily improved. Last year was the worst on record for India in terms of particulate pollution and the best in China. PM 2.5 levels across China fell by 17 per cent between 2010 and 2015, with quite a dramatic improvement towards 2015. China has instituted a broad, regionally-coordinated system of air pollution monitoring, installed high-tech pollution abatement equipment on a majority of its power plants, as well as devised means to restrict car ownership in major cities. It has also developed a network of 1,500 air quality monitoring stations in over 900 cities (India has only 39 such stations covering 23 cities). China’s coal use is down and coal-fired power plants are increasingly efficient. Significantly, China has instituted regional air quality regulations to ensure that air pollution is addressed jointly across city and state boundaries.

Is air pollution only a Delhi problem?

It is certainly not just a Delhi problem. The whole of northern India is dangerously polluted. In the latest WHO list, four of the world’s ten most polluted cities, in terms of annual average PM 2.5 levels, are Indian. They include Gwalior, Allahabad, Patna and Raipur (Delhi did not feature in the top 10). In fact, India has the dubious distinction of being home to 22 of the 50 most polluted cities globally. And these are only the cities we have data for.

With greater awareness, there is a lot of talk about masks and purifiers. Isn’t there a danger that the upper middle class will try to buy their way out of this mess?

The rich have already begun to insulate themselves from the dirty air. In India, those who can afford it have always dealt privately with the failures of public services provision. Air pollution presents new fault lines of inequality. As the poor continue to choke, the well-off can don expensive N-95 masks. This inequality is reinforced by the fact that it is outdoor, or ambient, air pollution that we are all so het up about. This is the air that even the rich breathe. But, household air pollution is an even worse public health emergency, associated with 1.04 million premature deaths a year. But since it is seen to mainly affect the poor, it makes fewer headlines. Up to 30 percent of ambient PM 2.5 concentrations in India are sourced to household pollution that escapes outdoors from dwellings. According to the 2011 Census, about 12 per cent of Delhi households, or over 12 lakh people, were still using these fuels. There is therefore self-interest, even for the rich, in addressing the problem. The middle classes cannot just buy their way out of dirty air. At best, masks etc are partial, short-term solutions. Bad air is democratic. It affects everyone.

When it comes to cleaning up the air, can a single-city focus work?

To impose measures to control air pollution in Delhi is pointless unless similar measures are also imposed on cities, small towns and fields of Punjab, Haryana, Rajasthan and UP. Even the most drastic policies, if centred around Delhi alone, will always be ineffective, because the wind does not obey city boundaries.

Finally, how long a haul is this?

One clear take-away from Beijing’s struggles that my book outlines is that this fight is a long-term one. Given the extreme levels of toxicity that cities like Delhi are grappling with, the air will probably continue to feel bad even as it gradually gets better. It will take Delhi between 15-25 years before changes are tangible and lasting, even if the government begins to take concerted action today.

Pallavi Aiyar’s Choked is exclusively available on the Juggernaut app.